Endometrioid ovarian carcinoma benefits from aromatase inhibitors: case report and literature review

Cancer-biomarkers associated with sex hormone receptors and recent therapeutic advancements: a comprehensive review

Hormones and its regulation plays vital role in causing breast, prostate, ovarian and endometrial cancers collectively known as hormone-sensitive cancers. This review discusses the various functions of the sex hormones and the biological pathways involved in causing hormone-associated cancer under differential regulation. We have also attempted to explore the biomarkers associated with the cancers and the current therapeutic availability to treat such cancers. Among various sex hormones such as estrogen, progesterone and androgen, estrogen the female sex hormone and its receptor had a major contribution in causing cancer and hence are considered a predominant target in treating the associated cancers. Other hormones and receptors such a androgen, progesterone, and their respective receptors were also reported to have a significant correlation in causing cancers. Apart from these receptors certain enzymes that act as precursors or as promoters are also targeted for treatment strategies. The drugs commonly used belong to the selective drug classes such as selective estrogen receptor modulators and selective progesterone receptor modulators. In the case of androgen regulation androgen deprivation therapies are practiced. It is also suggested that the use of natural substances to treat cancer could prevent resistance and reduce side effects. Identification of significant targets and the discovery of many efficient drugs shall be possible in the future with better understanding of hormone regulation and its influence on cancer causative mechanisms.

A Review of the Clinical Characteristics and Novel Molecular Subtypes of Endometrioid Ovarian Cancer

Ovarian cancer is one of the most common gynecologic cancers that has the highest mortality rate. Endometrioid ovarian cancer, a distinct subtype of epithelial ovarian cancer, is associated with endometriosis and Lynch syndrome, and is often accompanied by synchronous endometrial carcinoma. In recent years, dysbiosis of the microbiota within the female reproductive tract has been suggested to be involved in the pathogenesis of endometrial cancer and ovarian cancer, with some specific pathogens exhibiting oncogenic having been found to contribute to cancer development. It has been shown that dysregulation of the microenvironment and accumulation of mutations are stimulatory factors in the progression of endometrioid ovarian carcinoma. This would be a potential therapeutic target in the future. Simultaneously, multiple studies have demonstrated the role of four molecular subtypes of endometrioid ovarian cancer, which are of particular importance in the prediction of prognosis. This literature review aims to compile the potential mechanisms of endometrioid ovarian cancer, molecular characteristics, and molecular pathological types that could potentially play a role in the prediction of prognosis, and the novel therapeutic strategies, providing some guidance for the stratified management of ovarian cancer.

Estrogen Signaling and Its Potential as a Target for Therapy in Ovarian Cancer

The estrogen receptor (ER) has functionality in selected ovarian cancer subtypes and represents a potential target for therapy. The majority (>80%) of high grade serous, low grade serous and endometrioid carcinomas and many granulosa cell tumors express ER-alpha (ERα), and these tumor types have demonstrated responses to endocrine therapy (tamoxifen and aromatase inhibitors) in multiple clinical studies. Biomarkers of responses to these drugs are actively being sought to help identify responsive cancers. Evidence for both pro-proliferative and pro-migratory roles for ERα has been obtained in model systems. ER-beta (ERβ) is generally considered to have a tumor suppressor role in ovarian cancer cells, being associated with the repression of cell growth and invasion. The differential expression of the specific ERβ isoforms may determine functionality within ovarian cancer cells. The more recently identified G protein-coupled receptor (GPER1; GPR30) has been shown to mediate both tumor-suppressive and tumor-promoting action in ovarian cancer cells, suggesting a more complex role. This review will summarize recent findings in this field.

Ovarian Endometrioid Carcinoma Misdiagnosed as Mucinous Carcinoma: An Underrecognized Problem

Primary mucinous carcinoma of the ovary is uncommon, and while numerous studies have focused on improving our ability to distinguish these tumors from gastrointestinal metastases, recent data suggest that up to one fifth are still misdiagnosed with a previously underrecognized culprit: endometrioid carcinoma. Using an index case of an ovarian endometrioid carcinoma with mucinous differentiation masquerading as a mucinous carcinoma, we sought to identify the most efficient biomarker combination that could distinguish these 2 histotypes. Eight immunohistochemical markers were assessed on tissue microarrays from 183 endometrioid carcinomas, 77 mucinous carcinomas, and 72 mucinous borderline tumors. Recursive partitioning revealed a simple 2-marker panel consisting of PR and vimentin. The combination of PR absence and vimentin absence could predict mucinous tumors with a sensitivity of 95.1%, a specificity of 96.7%, and an overall accuracy of 96.0%. Additional marker combinations did not improve accuracy. The 5-yr ovarian cancer-specific survival for mucinous carcinoma was significantly worse than endometrioid carcinoma (70% vs. 86%, respectively, P=0.02). Our proposed 2-marker algorithm allows diagnostic distinction between mucinous and endometrioid ovarian carcinomas when morphology is not straightforward. Given key differences in the underlying biology and clinical behavior of these 2 histotypes, improved diagnostic precision is essential for guiding appropriate management and treatment.

Therapeutic options for mucinous ovarian carcinoma

OBJECTIVE

Mucinous ovarian carcinoma (MOC) is an uncommon ovarian cancer histotype that responds poorly to conventional chemotherapy regimens. Although long overall survival outcomes can occur with early detection and optimal surgical resection, recurrent and advanced disease are associated with extremely poor survival. There are no current guidelines specifically for the systemic management of recurrent MOC. We analyzed data from a large cohort of women with MOC to evaluate the potential for clinical utility from a range of systemic agents.

METHODS

We analyzed gene copy number (n = 191) and DNA sequencing data (n = 184) from primary MOC to evaluate signatures of mismatch repair deficiency and homologous recombination deficiency, and other genetic events. Immunohistochemistry data were collated for ER, CK7, CK20, CDX2, HER2, PAX8 and p16 (n = 117-166).

RESULTS

Molecular aberrations noted in MOC that suggest a match with current targeted therapies include amplification of ERBB2 (26.7%) and BRAF mutation (9%). Observed genetic events that suggest potential efficacy for agents currently in clinical trials include: KRAS/NRAS mutations (66%), TP53 missense mutation (49%), RNF43 mutation (11%), ARID1A mutation (10%), and PIK3CA/PTEN mutation (9%). Therapies exploiting homologous recombination deficiency (HRD) may not be effective in MOC, as only 1/191 had a high HRD score. Mismatch repair deficiency was similarly rare (1/184).

CONCLUSIONS

Although genetically diverse, MOC has several potential therapeutic targets. Importantly, the lack of response to platinum-based therapy observed clinically corresponds to the lack of a genomic signature associated with HRD, and MOC are thus also unlikely to respond to PARP inhibition.

The Importance of Steroid Uptake and Intracrine Action in Endometrial and Ovarian Cancers

Endometrial and ovarian cancers predominately affect women after menopause, and are more frequently observed in developed countries. These are considered to be hormone-dependent cancers, as steroid hormones, and estrogens in particular, have roles in their onset and progression. After the production of estrogens in the ovary has ceased, estrogen synthesis occurs in peripheral tissues. This depends on the cellular uptake of estrone-sulfate and dehydroepiandrosterone-sulfate, as the most important steroid precursors in the plasma of postmenopausal women. The uptake through transporter proteins, such as those of the organic anion-transporting polypeptide (OATP) and organic anion-transporter (OAT) families, is followed by the synthesis and action of estradiol E2. Here, we provide an overview of the current understanding of this intracrine action of steroid hormones, which depends on the availability of the steroid precursors and transmembrane transporters for precursor uptake, along with the enzymes for the synthesis of E2. The data is also provided relating to the selected transmembrane transporters from the OATP, OAT, SLC51, and ABC-transporter families, and the enzymes involved in the E2-generating pathways in cancers of the endometrium and ovary. Finally, we discuss these transporters and enzymes as potential drug targets.

Association of Hormone Receptor Expression with Survival in Ovarian Endometrioid Carcinoma: Biological Validation and Clinical Implications

This paper aims to validate whether hormone receptor expression is associated with longer survival among women diagnosed with ovarian endometrioid carcinoma (EC), and whether it identifies patients with stage IC/II tumors with excellent outcome that could be spared from toxic chemotherapy. Expression of estrogen receptor (ER) and progesterone receptor (PR) was assessed on 182 EC samples represented on tissue microarrays using the Alberta Ovarian Tumor Type (AOVT) cohort. Statistical analyses were performed to test for associations with ovarian cancer specific survival. ER or PR expression was present in 87.3% and 86.7% of cases, respectively, with co-expression present in 83.0%. Expression of each of the hormonal receptors was significantly higher in low-grade tumors and tumors with squamous differentiation. Expression of ER (Hazard Ratio (HR) = 0.18, 95% confidence interval 0.08–0.42, p = 0.0002) and of PR (HR = 0.22, 95% confidence interval 0.10–0.53, p = 0.0011) were significantly associated with longer ovarian cancer specific survival adjusted for age, grade, treatment center, stage, and residual disease. However, the five-year ovarian cancer specific survival among women with ER positive stage IC/II EC was 89.0% (standard error 3.3%) and for PR positive tumors 89.9% (standard error 3.2%), robustly below the 95% threshold where adjuvant therapy could be avoided. We validated the association of hormone receptor expression with ovarian cancer specific survival independent of standard predictors in an independent sample set of EC. The high ER/PR co-expression frequency and the survival difference support further testing of the efficacy of hormonal therapy in hormone receptor-positive ovarian EC. The clinical utility to identify a group of women diagnosed with EC at stage IC/II that could be spared from adjuvant therapy is limited.

Ovarian cancer treatment: The end of empiricism?

The diagnosis, investigation, and management of ovarian cancer are in a state of flux-balancing ever rapid advances in our understanding of its biology with 3 decades of clinical trials. Clinical trials that started with empirically driven selections have evolved in an evidence-informed manner to gradually improve outcome. Has this improved understanding of the biology and associated calls to action led to appropriate changes in therapy? In this review, the authors discuss incorporating emerging data on biology, combinations, dose, and scheduling of new and existing agents with patient preferences in the management of women with ovarian cancer.

Hormonal treatment in recurrent and metastatic gynaecological cancers: a review of the current literature

For many years hormonal treatment has played a role in the treatment of a selected group of patients with a variety of recurrent or metastatic gynaecological cancers, including ovarian and endometrial carcinomas, endometrial stromal sarcomas and granulosa cell tumours. Hormonal agents that are typically used include luteinizing-hormone-releasing hormone analogues, progestogens, selective oestrogen-receptor-modulating drugs such as tamoxifen, and more recently aromatase inhibitors. The rates of response to these drugs differ considerably depending on the tumour type, disease grade and stage as well as the type of drug used. Patients with granulosa cell tumours and endometrial stromal sarcomas have the highest response rates; owing to the rarity of these tumour types, the documented response rates are based on case reports and small series. Response rates in patients with recurrent and metastatic endometrial and ovarian carcinoma have been lower. It has been suggested that patients with well-differentiated and hormone-receptor-positive carcinomas are more likely to benefit from hormonal treatment. However, the data to support this are limited, and at times conflicting, with very few prospective studies to date. This review updates the evidence for the use of hormonal treatment in patients with potentially hormone responsive recurrent and metastatic gynaecological cancers.

Protein profiling of ovarian cancers by immunohistochemistry to identify potential target pathways

Background

To determine the protein expression profile (PEP) of primary and recurrent ovarian cancer patients in order to predict therapeutic targets for chemotherapy.

Methods

Tissue samples were submitted for PEP in two formats, including formalin-fixed paraffin-embedded tissue for immunohistochemistry (IHC) and fresh frozen tissue for oligonucleotide microarray (MA) gene expression assays. Specimens were analyzed for 18 protein markers and 88 MA genes. A series of Generalized Linear Models (GLM) was used to predict the proportion of positive results by histology for each biomarker.

Results

Four hundred and twenty-eight specimens were analyzed for IHC and 67 specimens for MA analysis. The majority of specimens, 82%, were serous histology and 35.3% of specimens were poorly differentiated. Sixty percent of specimens were advanced stage, 62% were from a primary diagnosis, and 53% were obtained from a metastatic site. BCRP, ER, MGMT, and RRM1 proteins were overexpressed in 85%, 47%, 93%, and 47% of serous carcinomas, respectively. The MGMT and RRM1 biomarkers were significantly overexpressed in serous (p < .001) and endometrioid (p = .01) histologies when compared to clear cell histology. MGMT was significantly elevated in 93% of serous and endometrioid samples, compared to 62% of samples with clear cell histology. Those proteins most often underexpressed included Her2/neu, SPARC, and c-kit, seen in less than 1%, 4%, and 5% of specimens, respectively.

Conclusions

PEP is a reliable and effective way of analyzing ovarian cancer specimens. PEP target identification does not appear to vary significantly with site evaluated, ovarian or other abdominal pelvic tissue, or primary versus recurrent disease. Variability in the expression of drug targets, including BCRP, ER, MGMT, and RRM1 could impact decision making pertaining to which therapeutic strategies carry the best chances for controlling disease.

Electronic supplementary material

The online version of this article (doi:10.1186/2053-6844-1-4) contains supplementary material, which is available to authorized users.